The present invention relaes to a ROTARY ENGINE and more particularly to a two cycle internal combustion rotary engine with pivotally swingable pistons.
Prior art internal combustion engines typically have a plurality of pistons each mounted in a separate cylindrical combustion chamber in parallel alignment. Each piston has a separate piston rod connected thereto and the piston rods are connected through a crankshaft and train of gears to impart rotational energy. These devices generate a substantial amount of friction and consume excessive power for various other reasons.
Rotary engines have been therefore relied upon to reduce friction and thereby increase efficiency. They can be made lightweight and compact and have desirable power-to-weight ratios. Furthermore, they are characteristically simple to cast and fabricate.
Rotary engines have been developed which act against a single cam track to convert lineal reciprocating motion of pistons mounted in combustion chambers formed on a rotor to rotary motion of the rotor. U.S. Pat. No. 2,439,150 to Smith is typical of such devices. The combustion chambers and pistons in these engines are uniformly cylindrical in shape. As the rotor rotates, the reciprocal movement of the piston and connecting piston rod imparts an undesirable lateral cocking moment on the piston sliding against the cylindrical wall as the followers move on the relative incline of the cam surface. This moment causes unbalanced stresses between the piston and cylindrical chamber wall and increases friction between them. This friction results in a reduction in efficiency of the engine and excessive stress and wear on the materials of the piston and cylinder wall.